This is a really odd problem, and I don't even think Sandboxie is to blame. I just hope someone will read this and point me in the right direction.

My Firefox 56 64bit will crash immediately on start, even before the UI shows up on screen or any network request is attempted. However, if I run it inside Sandboxie, it starts normally. I know it's weird. You can see details here: https://superuser.com/questions/1240608 ... dows-7-x64

I'd like to be able to use the browser normally (outside Sandboxie). If anyone has an idea about what I can try, please shoot.

I am not sure this is a Sandboxie issue, but I suggest you try the following:

- Remove any add-ons you may have installed (if you cannot do it on your host, give full access to Firefox profile in Sandboxie, and remove them there (if applicable) ).
- Try a new Firefox profile
- Disable Firefox multiprocess (e10s)
- Change Firefox sandbox level to 2, or even 0
- Re-install Firefox on your host (be sure to completely remove it including the appdata folder (make backups first) ).

Just to be clear: I don't think the problem is about Sandboxie. If I uninstall Sandboxie and re-install FF 64bit, the problem remains.

I think you guys maybe misunderstood me: FF 64bit works with no problem inside Sandboxie - I am running it right now. It is when I try to run it regularly (outside Sandboxie) that it crashes. I opened the issue here because I thought someone who has seen similar behavior -- even in other software -- might be able to give me some clue.

The link I posted in the OP has more information, including what I have already tried. Barb I have tried a lot of what you suggested already. Because the browser crashes before the UI even shows up, i can't really change settings. If I get rid of multiprocess (e10s), is there any advantage to using 64bit over 32bit?

If I get rid of multiprocess (e10s), is there any advantage to using 64bit over 32bit?

64 bits it is supposed to give better performance, less crashes.

FWIW, when I got my new W10 64 bits laptop in early July, I decided to install the 32 bits version of the browser, the reason being that it is supposed to be less buggy and gets along better with SBIE. All has worked well, no crashes, (I use 3 extensions) Firefox uses less than 150MB when it cold starts and haven't had any issue with Sandboxie. Perfect experience. I disable Multiprocess.

You might want to try switching to the 32 bits version and see what happens. Do a clean install of Firefox if you decide to test.

Thanks for your sugestion @bo.elam. I have already established that 32bit FF works well (see my link in the original post to the issue details). I am now trying to take advantage of FF's huge improvements in the 64bit version.

Basically what I'm hoping to understand is: what could explain the fact that an application crashes when run normally, but runs without problem inside Sandboxie?

A few more suggestions/questions:
Do other browsers (64 bits) work on your system? Is Firefox the only issue? Does it launch if you start your computer in Safemode?
You could try running procmon, save the logs (one for your Sandboxed Firefox, one for your non-sandboxed Firefox) and then compare them to see what's different.
If you have an antivirus software, or you used to have an antivirus software, run the uninstallers for them as there may be leftovers on your system causing issues.

I am going to move this topic to "Anything Else", since this is not a Sandboxie problem, as already established.

Regards,
Barb.-

PS: I won't be able to do much with your crash dmps, since this is not a Sandboxie related issue.